Over a century of commercial aviation, from the Ford Trimotor in the 1920s to today’s Boeing Co. and Airbus SE jetliners, there’s been one constant: Airplanes are virtually always long tubes sporting wings with engines bolted on underneath and a tail stabilizer at the back. Inside there’s a similarly standard layout—one or two aisles flanked by rows of seats, notwithstanding occasional extravagances such as staircases or bars for premium-class passengers.

Startup JetZero Inc. is taking aim at that design with a radical proposition: a triangle-shaped aircraft resembling a giant manta ray in the sky, boasting a shorter fuselage that’s wide enough to contribute to the lift needed to keep the thing airborne. Gone is the tail, with two engines piggybacked onto the rear taking its place to provide both power and stability.